Let's simplify each side of the equation:

Left side:
$10у+2\ast (7у-2)$ / 5
= $10у+14у-4$ / 5
= $24у-4$ / 5
= 24у / 5 - 4 / 5
= 4.8у - 0.8у
= 4у

Right side:
$5\ast (4у+3)+3у$ / 5
= $20у+15+3у$ / 5
= $23у+15$ / 5
= 23у / 5 + 15 / 5
= 4.6у + 3

Now, we have:
4у = 4.6у + 3

Subtracting 4.6у from both sides:
4у - 4.6у = 3
-0.6у = 3

Dividing by -0.6:
у = -5

So, the solution to the equation is у = -5.